I think maybe you're using the crappy type of valve extenders. Nobody would ever know I'm even using valve extenders if they were to look at my wheel, and it certainly doesn't operate any differently. Proper adapters thread right into where the valve core goes, and then the core goes into the extender. Both have rubber grommets to seal.
I have multiple sets of wheels with extenders and cant imagine what issues you're having. I did chuck the crappy style extenders that come with the wheels out into the trash bin of course.
To peaks. Have a good rep.
And its telling that even you had to toss the stock extenders. It does mean you have the added hassle of finding the right extender for your setup.